Liner releasing tool



June 9, 1964 K. A. WRIGHT ETAL 3,136,367

LINER RELEASING TOOL 2 Sheets-Sheet l Filed June 27, 1961 TM H GWM mouwL WSOW AWSN HHR TT .V EESN NNEI www. KKJ

ATTORNEYS.

IIIIIIIIIIIIIIIIIIIII'II'II Il IIIIIIIIIIIIIIIIHI'IIIIII June 9, 1964 K.A. WRIGHT ETAL 3,136,367

LINER RELEASING TooL Filed June 27, 1961 2 sheets-smeet 2 JAMES R.s

INVENT ATTORNEYS.

United States Patent O 3,136,367 LINER RELEASING TOOL Kenneth A. Wright,Los Angeles, Kenneth W. Solum,

Long Beach, and James R. Solum, Los Angeles,

Calif., assign'orsto B & W Incorporated, Torrance,

Calif., a corporation of California Filed June 27, 1961, Ser. No.120,065 12 Claims. (Ci. MSG- 208) This invention relates to a tool fromwhich a well pipe casing or liner may depend and which can release thewell pipe casing or liner as desired through particular predeterminedmovements.

In various operations in the drilling and completion of wells, it isoften desirable to release some lower portion of the well casing orliner which in turn remains in the well bore indefinitely or untilremoved by some other operation. One particular operation in which it isdesirable to release a well casing depending from a Well pipe or drillpipe is when the casing is cemented in the well bore prior to furtherand deeper drilling of the well. Another such operation is when a lineris cemented in the well bore in preparation for perforating and nalcompletion.

In each of the particular operations noted, and in Various otheroperations connected with the drilling and completion of wells, it hasbeen found advantageous in some situations to be able to rotate the holedrill string and well casing until just before the well casing or lineris released. For example, one of such situations is encountered whenrotating type scratchers are used to condition the well bore anddrilling mud therein in order to obtain a more homogenous and completecement iill of the annulus between the casing or liner and the wellbore. For rotating type scratchers to accomplish any useful function,the Well casing or liner supporting the scratchers must be rotated toagitate the drilling mud and abrade the Well bore. It has often beenfound that the longer this rotation can be continued during theplacement of the cement, the greater the opportunity is for a successfuland complete cement job.

The ever present danger of getting the drill pipe or Well pipe stuck inthe Well bore after the cement has once been introduced has resulted inthe current practice of terminating rotation of the drill string andwell casing long before the cement has been completely placed. yThispractice results in a time lapse of sufcient duration to permit some ofthe drillingr mud to gel so that the How of drilling mud in the annulusassumes a channeling condition whereby not all of the drilling mud inthe annulus is being displaced. As the cement is introduced in theannulus it also assumes this channeling condition established within thedrilling mud. With these physical conditions in the annulus, there is animperfect fill of cement and a resultant imperfect cementing of the Wellcasing and/or liner in the Well bore. However, if the drilling mud isthoroughly agitated and agitation is continued up 'to or including thetime when the cement enters the annulus then channeling is inhibitedsince the drilling mud is not permitted to gel. Agitation duringplacement of the cement has been found to promote a completedisplacement of the drilling mud by the cement slurry resulting in thepreferred cementing of the liner. In this specification, the word lineris intended to include the liner or casing supported by the releasingtool.

It is therefore the principal object of this invention to provide aliner releasing tool in which means are provided for rotating the lineruntil immediately preceding a release thereof.

Another object of this inventionis to provide a liner releasing tool inwhich means are provided for rotating a liner having from the tool andreleasing the liner by merely setting weight down on the releasing tooland continuing to rotate.

A further object of this invention is to provide a liner releasing toolin which means are provided for rotating or releasing the liner whereinthe liner cannot be released by mere axial movement of the releasingtool.

A still further object of this invention is to provide a liner releasingtool in which means are provided for releasing a liner which has becomestuck in the well bore without requiring either axial or rotationalmovement of the stuck liner.

A further object of this invention is to provide a liner releasing toolin which means are provided for releasing the liner by rotation of thedrill string or Well pipe above the releasing tool without regard forthe amount of weight resting downwardly on the releasing tool.

Other and more detailed objects and advantages of this invention willappear from the description in the accompanying drawings.

In the drawings:

FIGURE l isV an elevational view in partial section illustrating theinvention with the various parts thereof in relative position forrunning a liner in the hole.

FIGURE 2 is an elevational View partially sectioned with the variousparts of the invention in their relative positions during releasing ofthe liner.

FIGURE 3 is an elevational view partially sectioned with the casing orliner released and the releasing tool lifted away from the top of theliner.

FIGURE 4 is a sectional plan view taken substantially on the line 4-4 inFIGURE l.

FIGURE 5 is a sectional plan View taken substantially on the line 5-5 inFIGURE l.

FIGURE 6 is a sectional plan view taken substantially on the line 6-6 inFIGURE 2.

FIGURE 7 is an elevational view of the releasing tool of this inventionattached to the top of a liner hanger set in a casing with the tool ofthis invention in a position for releasing from the liner hanger.

Referring now to the drawings, the liner releasing tool assembly,generally designated 1t), may be secured to the top of a casing coupling11 by standard threads 12 and the liner 13 to be released is attached tothe casing coupling 11. The releasing tool assembly 10 may have a wellor drill pipe 14 attached to its upper end by standard threads 15 forrunning the tool assembly 10 and liner 13 into the well bore and foroperating the tool assembly 10 to release the liner 13 and lift thatpart of the tool assembly 10 out of the well borewhich does not remainattached to the liner.

A mandrel 16 of the tool assembly 10 extends substantially the length ofthe assembly and may be attached to a wash or tail pipe 17 at its lowerend by threads 18. A sleeve assembly, generally designated 19, has acollar member 20 and a sleeve extension 21 connected by threads 22. Thecollar member 20 has an internal bore 23 adapted for slidable androtatable engagement with the external cylindrical surface 24 of themandrel 16.

An elongated sleeve or bushing 25 has an internal bore 26 adapted forslidable and rotatable engagement with the external cylindrical surface27 of the mandrel 16. The upper end of the bushing 25 has an externallyupset portion 28 forming a downwardly facing shoulder 29. A cooperatingand upwardly facing shoulder 30 is formed on the sleeve extension 21 tosupport and retain the bushing 25 within the sleeve assembly 19.

A connector collar 31 of tool assembly 10 is provided for connecting theassembly to the collar 11 through threads 12. The upper end of thecollar 31 has an internal thread 32 adapted to threadedly engage theexternal thread 33 on the lower end of the bushing 25.

When the liner has been-released as hereinafter described, the connectorcollar 31 remains attached to the liner through threads 12 and, asillustrated in FIGURE 3, is not removed from the well bore with theremainder of the tool assembly 10.

MeansA are provided for selectively rotating either the internal bores23 and 26 of the collar member 20 and bushing 25, respectively. With theliner 13 hanging from the releasing tool 1t), the lugs 34 engage theslots 35 of the collar member as best illustrated in FIGURE 4 so thatrotation of the mandrel 16 causes rotation of the sleeveV assembly 19which in turn causes rotation of the connector collar 31 which resultsin rotation of the liner 13, as desired. Relative rotation of the sleeveextension 21 and the connector collar 31 when the tool is assembled asillustrated in FIGURE l, is prevented by means of axially extending lugs37 on the lower end of the sleeve 21 which extendinto slots 38 in theupper end of the connector collar 31.

In order to release the liner 13, the mandrel 16 is lowered relative tothe sleeve assembly 19, collar 31, bushing 2,5 and liner 13 so that thelugs 34 on the mandrel engage the slots 36 in the bushing 25 asillustrated in FIGURE 2. With the various parts of the releasing toolassembly 10 in this position, rotation of the mandrel 16 causes rotationof the bushing 25 relative to the connector collar 31 therebyunthreading the threads 32 and 33. Although threads 32 and 33 could beright-hand, we prefer to make them left-hand threads so that inaccordance with accepted drilling and completion practices, the drillpipe 14 is rotated in a Vright-hand direction to accomplish theunthreading of the threads 32 and 33, and such right-hand rotation willnot inadvertently unthread the drill pipe couplings or casing couplingswhich are normally righthand threads. In order to accomplish thedownward movement of the mandrel 16 relative to the remainder of thetool assembly 10, liner 13 is rested on the bottom of the hole orotherwise supported within the well bore.

Means may be provided for promoting the ease of rotation ofthe mandrel16 when lowered relative to the remainder of the tool assembly, and asshown in the Vdrawings, these means may include a thrust bearingassembly, generally designated 39, connecting the mandrel 16 to the`drill pipe 14 through the threads 15. This bearing assembly 39 may becomprised of coupling member 4t) engaging the drill pipe 14 throughthreads 15 which is threadedly connected to the upper end of the mandrel16 by threads 41, and a thrust flange 42 rotatably mounted on themandrel 16 with a plurality of bearing balls 43 entrapped between thecoupling member and the thrust ange 42. A set screw 44 is threadedlyreceived in the coupling member 46 for engaging the upper end of themandrel 16 to prevent inadvertent unthreading of the coupling memberfrom the mandrel. An upwardly facing shoulder 45 on the mandrel 16limits vthe axial downward movement of the thrust lange 42 relative tothe coupling member 40, thus retaining the bearing balls 43 entrappedbetween the coupling and the flange. As the mandrel 16 is loweredrelative to the sleeve assembly 19, the downward facing surface 46 ofthe thrust flange 42 frictionally engages Vthe upward facing surface 47of the collar member 20 as illustrated in FIGURE 2, whereby rotation ofthe drill pipe 14 and coupling Aiuto rotate the mandrel 16 results inrelative rotation between the coupling 40 and the iiange 42. Thus, itmay be seen that the downward force on the coupling 40 is transmitted tothe bearing balls 43 to the flange 42 and thence through the sleeveassembly 19 to the connector collar 31 and to the liner 13, therebypreventing any thrust loading on the bushing 25 as it is beingUnthreaded from the connector collar 31;

Sufficient axial space is provided between the collar member 20 and theupper end of the bushing 25 to permit complete unthreading of threads 32and 33 without axial separation of sleeve extension 21 and connectorcollar 31. The slots 36 in the bushing 25 are also of sucient length topermit the above-described unthreading without axial movement of themandrel 16 to maintain engagement of the lugs 34 in the slots 36.

When the threads 32 and 33 have been completely separated furtherrotation of the mandrel has no effect, and thus accurate counting orestimating the number of turns necessary to release the liner is notrequired, thereby eliminating one of the inherent weaknesses in manycomnercial tools of this type. Upon lifting the drill pipe 14, thereleasing tool may be removed from the hole as illustrated in FIGURE 3,leaving the connector collar 31 threadedly mounted on the liner.

Various O-ring grooves and O-ring seals 48 are pro vided to permitpre-packing of the releasing tool with the proper lubricants, and theseseals serve to inhibit the contamination of the lubricants by foreignmatter within the well bore. The pre-lubrication'assures the properreleasing of the threads 32 and 33 and the proper axial movement of themandrel relative to the various other parts of the tool assembly.

In order to assemble the releasing tool the collar member 2t) must beinserted onto the upper end of the mandrel 16 before the bearingassembly 39 is installed and the bushing 25 must be inserted onto thelower end of the mandrel 16 before the sleeve extension 21 is threadedonto the collar member 2G at thread means 22. In order to connect theconnector collar 31 to the assembly, the lugs 37 of sleeve lextension 21are positioned in the slots 3S of the connector collar 31 and the lugs34 of mandrel 16 are lowered into the slots 36 of the bushing 25 wherebyleft-hand rotation of the mandrel 16 threadedly connects the threads 32and 33. The threads 32 and 33 are engaged to the position where theshoulders 29 and 30 of the bushing 25 andrsleeve extension 21,respectively, become engaged thereby securing the sleeve extension 21 tothe connector collar 31.

As illustrated in FIGURE 7; the releasing tool assembly 10 may beincorporated with a liner hanger, generally designated 50, when it isundesirable to rest the casing or liner 13 on the bottom of the wellbore. To maire proper userof the releasing tool by rotation of the linerbefore and during the placing of the cement, it is necessary to providea liner hanger 50 which does not set upon rotation and, in fact, weprefer to use a liner hanger which may be set by mere. axial movementsuch as the hanger which is the subject of our now issued patent on ourcopending application entitled Slip Actuating Mechanism, Patent No.3,012,612, issued December 5, 1961. The upper end 51 of the `linerhanger may be machined similar to the connector collar 31 including theinternal threads 32 and the slots 38 so that the sleeve extension 21 andthe bushing 25 engage the upper end 51 of the hanger in the same mannerthat they engage the connector collar 31 heretofore described. Thus,with the slips 52 of the hanger 50 engaging the well casing 53previously cemented in the well bore, the drill pipe 14 may be rotatedto separate the releasing tool assembly 10 from the upper end 51 of theliner hanger 50 as described above relative to FIGURES 2, 3 and 6.

From the foregoing, it may be seen that a liner-releasing tool isprovided which is capable of quickly releasing a liner by merelylowering the drill pipe and rotating. This release may be affected eventhough the liner has become stuck and yet inadvertent release of theliner can be safely avoided by merely not rotating the drill pipe whentheweight of the drill pipe is down on the liner.

Havingfully described our invention, it is to be understood that we donot wish to be limited to the details herein set forth or to the detailsillustrated in the drawings,

but our invention is of the full scope of the appended claims.

We claim:

l. In a well tool for releasing a Well pipe or the like having an upperend provided with thread means and upwardly facing slot means, thecombination of: a mandrel, a sleeve slidably and rotatably mounted onsaid mandrel, lug means on said sleeve for engaging the slot means ofthe well pipe upper end to transmit rotational movement from said sleeveto the Well pipe, a bushing slidably and rotatably mounted on saidmandrel and having thread means for threaded engagement with the threadmeans on the well pipe upper end, and means carried by said mandrel forselectively engaging either said sleeve or said bushing upon axialmovement of said mandrel to rotate either the sleeve or bushing uponrotation of said mandrel.

2. In a well tool for releasing a well pipe or the like having an upperend provided with thread means and upwardly facing slot means, thecombination of: a mandrel, a sleeve slidably and rotatably mounted onsaid mandrel, lug means on said sleeve for engaging the slot means ofthe well pipe upper end to transmit rotational movement from said sleeveto the well pipe, said sleeve having internal slots adjacent saidmandrel, aL bushing slidably and rotatably mounted on said mandrel andhaving thread means for threaded engagement with the thread means on thewell pipe upper end, said bushing having internal slots adjacent saidmandrel, and means carried by said mandrel for selectively engaging thesaid slots in either said sleeve or said bushing upon axial movement ofthe mandrel to rotate either the sleeve or the bushing upon rotation ofsaid mandrel.

3. In a well tool for releasing a well pipe, the combination of: amandrel, a sleeve slidably and rotatably mounted on said mandrel, acollar for connecting to the well pipe, interengaging means on saidsleeve and said collar for transmitting rotational movement of saidsleeve to said collar, thread means on said collar, a bushing slidablyand rotatably mounted on said mandrel and having thread means forthreaded connection with said thread means on said collar, engageablemeans on said sleeve and on said bushing, and means carried by saidmandrel for selectively engaging said engageable means of either saidsleeve or said bushing upon axial movement of the mandrel to rotateeither the sleeve or bushing upon rotation of said mandrel.

4. In a well toolr for releasing a Well pipe, the combination of: amandrel, a sleeve slidably and rotatably mounted on said mandrel, acollar for connecting to the well pipe, interengaging means on saidsleeve and said collar for transmitting rotational movement of saidsleeve to said collar, thread means on said collar, a bushing slidablyand rotatably mounted on said mandrel and having thread means forthreaded connection with said thread means on said collar, engageablemeans on said sleeve and on said bushing, means on said bushing forengaging said sleeve to maintain said'interengaging means in engagementwhile Said bushing is connected to said collar by said thread means, andmeans carried by said mandrel for selectively engaging said engageablemeans of either said sleeve or said bushing upon axial movement of themandrel to rotate either the sleeve or bushing upon rotation of saidmandrel.

5. In a well tool for releasing a well pipe, the combination of: amandrel, a sleeve slidably and rotatably mounted on said mandrel, saidsleeve having internal slots adjacent said mandrel, a collar forconnecting to the well pipe, interengaging means on said sleeve and saidcollar for transmitting rotational movement of said sleeve to saidcollar, thread means on said collar, a bushing slidably and rotatablymounted on said mandrel and having thread means for threaded connectionwith said thread means on said collar, said bushing having internalslots adjacent said mandrel, and means carried by said mandrel forselectively engaging the said slots in either said sleeve or saidbushing upon axial movement of the mandrel to rotate either the sleeveor the bushing upon rotation of said mandrel.

6. In a well tool for releasing a well pipe, the combination of amandrel, a sleeve slidably and rotatably mounted on said mandrel, saidsleeve having slots adjacent said mandrel, a collar for connecting tothe well pipe, interengaging means on said sleeve and said collar fortransmitting rotational movement of said sleeve to said collar, threadmeans on said collar, a bushing slidably and rotatably mounted on saidmandrel and having threaded means for threaded connection with saidthread means on said collar, said bushing having internal. slotsadjacent said mandrel, means on said bushing for engaging said sleeve tomaintain said interengaging means in engagement while said bushing isconnected to said collar by said thread means, and means carried by saidmandrel for selectively engaging the said slots in either said sleeve orsaid bushing upon axial movement of the mandrel to rotate either thesleeve or the bushing upon rotation of said mandrel.

7. In a well tool for rotating and releasing a well pipe or the like,the combination of: a mandrel, a drive sleeve having a lower end, saidsleeve slidably and rotatably mounted on said mandrel,` an internalupwardly facing shoulder on the said lower end of the sleeve, a bushingslidably and rotatably mounted on said mandrel and within said sleeve,said bushing having an upper and lower end, a downwardly facing shoulderon said bushing upper end for engaging said upwardly facing shoulder onsaid sleeve to limit axial movement of said bushing downwardly relativeto said sleeve, thread means on the said lower end of the bushing, aconnector collar having a lower end with means for connection to a wellpipe or the like, an upper end on said collar'having thread means forengaging said bushing thread means, interengaging means on said sleeveand said collar for transmitting rotational movement of said sleeve tosaid collar, engageable means on said sleeve and on said bushing, andmeans carried by the mandrel for selectively engaging said engageablemeans of either the said sleeve or said bushing upon axial movement ofsaid mandrel to rotate either the sleeve or the bushing upon rotation ofsaid mandrel.

8. In a well tool for rotating and releasing a well pipe or the like,the combination of a mandrel, a drive sleeve having an upper and lowerend, an inwardly extending flange on the said upper end of the sleeveslidably and rotatably engaging the said mandrel, an internal upwardlyfacing shoulder on the said lower end of the sleeve, a bushing slidablyand rotatably mounted on said mandrel and within said sleeve, saidbushing having an upper and lower end, a downwardly facing shoulder onsaid bushing upper end for engaging said upwardly facing shoulder onsaid sleeve to limit axial movement of said bushing downwardly relativeto said sleeve, thread means on the said lower end of the bushing, aconnector collar having a lower end with means for connection to a wellpipe or the like, an upper end on said collar having thread means forengaging said bushing thread means, interengaging means on said sleeveand said collar for transmitting rotational movement of said sleeve tosaid collar, a noncircular inner surface on the said upper end of thesleeve, a similar non-circular inner surface in said bushing, and asimilarly shaped non-circular enlarged portion on said mandrel wherebythrough axial movement of said manthe non-circular enlarged portion mayengage the` like inner surfaces of either the sleeve or the bushing tocause rotation thereof upon rotation of said mandrel.

9. In a well tool for rotating and releasing a well pipe or the like,the combination of: a mandrel, a drive sleeve having an upper and lowerend, an inwardly extending flange on the said upper end of the sleeveslidably and rotatably engaging the said mandrel, an internal upwardlyfacing shoulder on the said lower end of the sleeve, a bushing slidablyand rotatably mounted on said mandrel and within said sleeve, saidbushing having an upper and lower end, a downwardly facing shoulder onsaid bushing upper end for engaging said upwardly facing shoulder onsaid sleevetto limit axial movement of said bushing downwardly relativeto said sleeve, thread means on the said lower end of the bushing, atleast one downwardly extending lug on the said lower end of 'the sleeve,a conneetor collar having a lower end with means for connection to awell pipe or the like, an upper end on said collar having thread meansfor engaging said bushing thread means and also a slot for receiving thesaid lug on the lower end of the sleeve, a non-circular inner surface onthe said upper end of the sleeve, a similar non-circular inner surfacein said bushing, and a similarly shaped noncircular enlarged portion onsaid mandrel whereby through axial movement of said mandrel 'thenon-circular enlarged portion may engage the like inner surfaces ofeither the sleeve or the bushing to cause rotation thereof upon rotationof said mandrel.

10. In a well tool for rotating and releasing a Well pipe or the like,the combination of: a mandrel, a drive sleeve having an upper and lowerend, an inwardly extending lange on the said upper end of the sleeveslidably and rotatably engaging the said mandrel, an internal upwardlyfacing shoulder on the said lower end of the sleeve, a bushing slidablyand rotatably mounted on said mandrel and within said sleeve, saidbushing having an upper and lower end, a downwardly facing shoulder onsaid bushing upper end for engaging said upwardly facing shoulder onsaid sleeve to limit axial movement of said bushing downwardly relativeto said sleeve, thread means on the said lower end of the bushing, atleast one downwardly extending lug onthe said lower end of the sleeve, aconnector collar having a lower end with means for connection to a wellpipe or the like, an upper end on said collar having thread means forengaging said bushing thread means and also a slot for receiving thesaid lug on the lower end of the sleeve, a non-circular inner surface onthe said upper end of the sleeve, a similar non-circular inner surfacein said bushing, a similarly shaped noncircular enlarged portion on saidmandrel whereby through axial movement of said mandrel the non-circularenlarged portion may engage the like inner surfaces of either the sleeveor the bushing to cause rotation thereof upon rotation of said mandrel,and the said sleeve ilange engaging the enlarged portion of said mandrelto limit relative axial movement of said sleeve and mandrel.

11. In a well 'tool for rotating and releasing a well pipe or the like,the combination of: a mandreLa drive sleeve having an upper and lowerend, an inwardly extending flange on the said upper end of the sleeveslidably and rotatably engaging the said mandrel, an internal upwardlyfacing shoulder on the said lower end of the sleeve, a bushingslidably'and rotatably mounted on said mandrel and within said sleeve,said bushing having an upper and lower end, a downwardly facing shoulderon said bush- Ving upper end for engaging said upwardly facing shoulderon said sleeve to limit axial movement of said bushing downwardlyrelative to said sleeve, thread means on the said lower end of thebushing, at least one downwardly extending lug on the said lower end ofthe sleeve, a connector collar having a lower end with means forconnection to a well pipe or the like, an upper end on said collarhaving thread means for engaging said bushing thread means and also aslot for receiving the said lug on the lower end of the sleeve,` anon-circular inner surface on the said upper end of the Sleeve and belowsaid flange, a similar nonecircular inner surface in said bushing, amating non-circular enlarged portion on said mandrel whereby throughaxial movement of said mandrel the noncircular enlarged portion mayengage the like inner surfaces of either the sleeve or the bushing tocause rotation thereof upon rotation of said mandrel, the said sleeveflange engaging the enlarged portion of said mandrel to limit relativeaxial movement of said sleeve and mandrel, and bearing means mounted onthe upper end of said mandrel for engaging the said sleeve ilange upondownward movement of said mandrel relative to said sleeve whereby axialdownward forces are transmitted from the mandrel through the bearingmeans, through the sleeve, through the connector collar to the well pipeto permit relative free upward movement of said bushing in releasing thecooperating thread means upon rotation of said mandrel.

12. In a well tool for hanging and releasing a well pipe, within a wellcasing, the combination of: a hanger assembly having means for hanging awell pipe inside the well casing, said hanger assembly having upper yandlower ends, said lower end connected to the well pipe, a mandrel, asleeve slidably and rotatably mounted on said mandrel, interengagingmeans on said sleeve and said upper end of the hanger for transmittingrotational movement of said sleeve to said hanger, thread means on thesaid upper end of the hanger, a bushing slidably and rotatably mountedon said mandrel and having thread tion of said mandrel.

References Cited in the file of this patent,

UNITEDv STATES PATENTS 1,870,779 Layne et al Aug. 9, 1932 1,982,915Jenks Dec. 4, 1934 2,097,755 Brown ,Nov. 2, 1937 2,307,275 Johnson Jan.5, 1943 2,500,276 y Church Mar. 14, 1950 2,670,045 Armentrout Feb. 23,1954 3,002,561 Baker et al.` Oct. 3, 1961 3,006,414 Burns Oct. 31, 1961

1. IN A WELL TOOL FOR RELEASING A WELL PIPE OR THE LIKE HAVING AN UPPEREND PROVIDED WITH THREAD MEANS AND UPWARDLY FACING SLOT MEANS, THECOMBINATION OF: A MANDREL, A SLEEVE SLIDABLY AND ROTATABLY MOUNTED ONSAID MANDREL, LUG MEANS ON SAID SLEEVE FOR ENGAGING THE SLOT MEANS OFTHE WELL PIPE UPPER END TO TRANSMIT ROTATIONAL MOVEMENT FROM SAID SLEEVETO THE WELL PIPE, A BUSHING SLIDABLY AND ROTATABLY MOUNTED ON SAIDMANDREL AND HAVING THREAD MEANS FOR THREADED ENGAGEMENT WITH THE THREADMEANS ON THE WELL PIPE UPPER END, AND MEANS CARRIED BY SAID MANDREL FORSELECTIVELY ENGAGING EITHER SAID SLEEVE OR SAID